Pupillary reflex imaging

ABSTRACT

A method, system and device for recording image data for a pair of eyes exposes to a series of flashes that includes flashes that vary chromatically is provided. More particularly, one eye is exposed to the series of flashes, and the resulting pupillary reflexes of both eyes are concurrently recorded.

REFERENCE TO PRIOR APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/873,296, now U.S. Pat. No. 7,488,073, which was filed on 16 Oct.2007, which is a continuation of U.S. Utility patent application Ser.No. 10/641,435, now U.S. Pat. No. 7,334,895, which was filed on 15 Aug.2003, and which claims the benefit of co-pending U.S. ProvisionalApplication Ser. No. 60/404,000 and U.S. Provisional Application Ser.No. 60/404,232, both filed on 16 Aug. 2002, all of which are herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention generally relates to a method, system and device forobtaining data that can be used to detect ocular dysfunctions. Moreparticularly, the invention provides a method, system and device forexposing one or both eyes to a series of light flashes and measuring thedirect and/or consensual pupillary reflexes that can be used to detectthe presence of various dysfunctions and/or disorders.

2. Background Art

During eye examinations, the pupillary reflexes of a patient are oftenmonitored to determine the presence of various ocular dysfunctions. Thepresence of one or more ocular dysfunctions can signal that the patientsuffers from an ocular disorder such as optic neuropathy, otherpathology of the ocular pathways between the photoreceptors of theretina and brain, opacification of the ocular media, or conditions thatimpact the transmission of light through the ocular media. A commonobjective visual functional test for the detection of such visualdysfunctions is the “Swinging Flashlight Test” (SFT). For the SFT, ahandheld, very bright light source is shined first into one eye of thepatient and then into the other eye, in a pendular fashion with a periodof one to two seconds. While this is being done, the examiner willobserve the reflexes of the patient's pupils. A detection of a positivesign is made based on the observed reflexes.

For example, if the light is shined into an eye that has an optic nerveconduction defect, while the other eye does not, the pupil of the eyewith the defect, will contract to a lesser degree than will the pupil ofthe eye without the defect when that eye is stimulated with the samelight. Similarly, if both eyes have a defect, one having a greaterdefect than the other, the light being shined into the eye with thegreater defective optic nerve will evoke a lesser pupillary contractionof both pupils than would the same light shown into the eye with thelesser optic nerve defect, thus yielding the sign of a Relative AfferentPupillary Defect (RAPD). Moreover, in the presence of a RAPD, when thelight is alternated every few seconds between the two eyes, thesedifferences in pupillary reflexes to the same bright light shined intothe two eyes may give rise to an “illusion” that shining the same brightlight into the eye with the greater defect caused its pupil to dilate(or expand), a so called Marcus-Gunn pupil.

The SFT is a foremost example of an objective functional test of thevisual system that depends upon differences in pupillary reflexes toinfer the presence of an ocular dysfunction, and therefore an oculardisorder (i.e., disease or pathology). However, this test has numerousdrawbacks. In particular, it lacks specificity for any one oculardisorder whether of neurological or transmissive origin. It can bepositive in unilateral dense cataracts, in certain unilateral retinaldisorders, in anisocoria, as well as in significant asymmetric glaucoma.The clinician can not tell which ocular disorder is present based on thepupillary reflexes alone. Moreover, the SFT lacks sensitivity due to themanner in which the differences between the direct and consensualreflexes are observed. For example, the clinician can not observe thepupils of both eyes simultaneously, but must visualize the reflex of onepupil first and then visualize the reflex of the other pupil momentslater. As a result, small differences in reflexes may go unnoticed. Theunaided observation makes this comparative judgement subject tosignificant error and makes the detection of small differences inreflexes between the two eyes especially problematic. Because the SFTrelies on the examiner's naked eye to detect and diagnose oculardysfunctions, it lacks practical utility. Moreover, by depending on asingle bright light, the SFT stimulates the visual system in anindiscriminate manner. As a result, this manner of evoking the pupils'reflexes, has proven to be lacking in both sensitivity and specificity.

Further, several observations have been made concerning the oculardisorder glaucoma, thought to be a form of optic neuropathy. First,glaucoma and glaucoma suspect patients display a significant degree ofdyschromatopsia, i.e., deficiencies in color discrimination. Second,patients with asymmetric glaucoma, as measured by visual field loss andcup-disc ratios, manifest gross afferent pupillary defects to a greaterextent than do patients without glaucoma. Third, a consensual pupillaryreflex can be induced by the interchange of equally luminous,heterochromatic members of a pair of monochromatic lights shined intothe patient's contralateral eye. This finding must mean that chromaticdifferences in stimuli, activate pupillary reflexes via stimulation ofdifferent cell populations independently of the luminosity change thatis thought to be the primary basis of the pupillary reflex activation inthe SFT.

Although not previously brought to bear on detecting specific oculardysfunctions, attempts have been made to solve these problems byimplementing systems and devices for measuring pupillary reflexes tolight stimuli. Such devices generally implement a system for exposing apatient's eyes to stimuli and then measuring the pupillary reactionthereof In particular, the goal is to intentionally induce a pupillaryreflex and then measure the reflex using various means. Sincedimensional changes in the pupil's movements can often be minuscule, thecomparison to a range of “normal” reactions obtained from differentpatients can lack accuracy. Without an appropriate validation procedure,this could lead to either a false diagnosis of a disorder that is notpresent, a failure to diagnose a disorder that is present, or a failureto distinguish between two ocular diseases. Furthermore, if the examineris seeking specific information, for example, about the afferent opticnerve pathology of a patient, efferent deficiencies may significantlyconfound the interpretation of such sought for information.

Therefore there exists a need for a method and device that allow for thesensitive and accurate recordation and/or comparison of the pupillaryreflexes of a patient's eyes to a series of flashes that target specificcell populations of the visual system. Moreover, there is a need for amethod, system and device that are able to differentiate between variousasymmetries of afferent or efferent origin, whether revealed in theafferent or the efferent branches of the pupillomotor system, andwhether they be of retinal, ocular, illuminometric, or optic nerveorigin.

SUMMARY OF THE INVENTION

The invention provides a method, system and device for obtaining datathat can be used to detect an ocular dysfunction in a patient. Inparticular, a first eye is exposed to a series of flashes in which eachflash varies chromatically from the other flashes in the series.Pupillary reflexes for both eyes are measured during the exposures. Thepupillary reflexes can then be evaluated to determine if an oculardysfunction is present. In one embodiment, both eyes are alternatelyexposed to the same series of flashes. Further, additional series offlashes that vary by location in the visual field and/or luminosity(i.e., brightness) can be incorporated and evaluated.

A first aspect of the invention provides a method of detecting an oculardysfunction in a patient, the method comprising the steps of: exposing afirst eye to a first series of flashes, wherein each flash in the firstseries of flashes varies chromatically from the other flashes;concurrently measuring pupillary reflexes of the first eye and a secondeye of the patient during the exposing step; and evaluating thepupillary reflexes to determine if the ocular dysfunction is present.

A second aspect of the invention provides a method of detecting anocular dysfunction in a patient, the method comprising the steps of:exposing a first eye of the patient to a series of flashes generated bya first light source, wherein each flash in the series of flashes varieschromatically from the other flashes in the series of flashes; exposinga second eye of the patient to the series of flashes generated by asecond light source; altering a luminosity of the first and second lightsources; repeating the exposing steps using the altered luminosities;altering a location of the first and second light sources in the visualfields of the first and second eyes; repeating the exposing steps usingthe altered locations; concurrently recording pupillary reflexes of thefirst eye and the second eye during each exposing step; and evaluatingthe recorded pupillary reflexes to determine if the ocular dysfunctionis present.

A third aspect of the invention provides a system for detecting anocular dysfunction, comprising: a first eye scope for exposing a firsteye to a series of flashes and detecting a pupillary reflex of the firsteye for each flash, the first eye scope having an ocular aperture, alight aperture, and a monitoring aperture; a second eye scope fordetecting a pupillary reflex of a second eye for each flash, the secondeye scope having an ocular aperture and a monitoring aperture; a firstlight source for generating the series of flashes through the lightaperture, wherein each flash in the series of flashes varieschromatically from the other flashes; and a measurement system forconcurrently measuring the pupillary reflexes of the first eye and thesecond eye based on light passing through the monitoring apertures.

A fourth aspect of the invention provides a device for detecting anocular dysfunction, comprising: a first eye scope for exposing a firsteye to a series of flashes and detecting a pupillary reflex of the firsteye for each flash, the first eye scope having an ocular aperture, alight aperture, and a monitoring aperture; a second eye scope fordetecting a pupillary reflex of a second eye for each flash, the secondeye scope having an ocular aperture and a monitoring aperture; and afirst light source for generating the series of flashes through thelight aperture, wherein each flash in the series of flashes varies by atleast one of: chromatically, location in the visual field, andluminosity from the other flashes in the series of flashes.

A fifth aspect of the invention provides a device for detecting oculardysfunctions that comprises: (1) a light emitting sphere having: (a) anexit port; (b) an outer portion positioned along a periphery of the exitport, wherein the outer portion has a light source disposed thereon; and(c) a reflective well portion, wherein light emitted from the lightsource shines from the outer portion to the reflective well portion, andwherein the light reflects off the reflective well portion and exits thelight emitting sphere through the exit port as a single beam of light.

The illustrative aspects of the invention are designed to solve theproblems herein described and other problems not discussed, which arediscoverable by a skilled artisan.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will be more readilyunderstood from the following detailed description of the variousaspects of the invention taken in conjunction with the accompanyingdrawings in which:

FIG. 1A is a top view of a device according to one aspect of theinvention;

FIG. 1B is perspective view of a system that includes the device shownin FIG. 1A according to another aspect of the invention;

FIG. 2 is a cross-sectional view of a light emitting sphere according tostill another aspect of the invention;

FIG. 3 shows a recorded image of an eye according to yet another aspectof the invention;

FIG. 4 shows a recorded image of an eye that includes an overlay featureaccording to another aspect of the invention;

FIG. 5A shows a recording of direct and consensual pupillary reflexesevoked by a flash exposed to the left eye of a patient according to oneaspect of the invention;

FIG. 5B shows a recording of direct and consensual pupillary reflexesevoked by a flash exposed to the right eye of a patient according toanother aspect of the invention;

FIG. 6 shows illustrative method steps according to one aspect of theinvention;

FIG. 7 shows illustrative method steps according to another aspect ofthe invention; and

FIG. 8 shows an illustrative set of inter-correlation matricesconstructed according to yet another aspect of the invention.

It is noted that the drawings of the invention are not to scale. Thedrawings are intended to depict only typical aspects of the invention,and therefore should not be considered as limiting the scope of theinvention. In the drawings, like numbering represents like elementsbetween the drawings.

DETAILED DESCRIPTION OF THE INVENTION

As stated above, the invention provides a method, system and device forobtaining data that can be used to detect an ocular dysfunction in apatient. In particular, a first eye is exposed to a series of flashes inwhich each flash varies chromatically from the other flashes in theseries. Pupillary reflexes for both eyes are measured during theexposures. The pupillary reflexes can then be evaluated to determine ifan ocular dysfunction is present. In one embodiment, both eyes arealternately exposed to the same series of flashes. Further, additionalseries of flashes that vary by location in the visual field and/orluminosity (i.e., brightness) can be incorporated and evaluated.

As a result, the invention can target different visual functions andcell populations by incorporating series of flashes that varychromatically, luminosity, and/or by location in the visual field. Eachflash comprises a beam of light having a short time duration. In oneembodiment, each flash is terminated before the release (escape) phaseof the pupillary reflex has begun, for example, after approximately 0.6seconds. This allows for a substantial increase in the number ofdistinct afferent and efferent reflex pathways that can be probed byusing the invention rather than the SFT. By probing a larger number ofpathways, a highly discriminative and sensitive measure of any opticneuropathology that may manifest itself in any of the differentconductive ocular pathway pathologies can be obtained, and permits aseparate assessment of efferent pathology. The data provided by theseries of flashes can be processed to detect afferent optic nerve orefferent pupillary asymmetry. Further, the data can provide a directionsensitive measurement of pupillary reflexes in both eyes. Consequently,the invention can provide sufficiently sensitive measurements toevaluate asymmetric precursory manifestations (i.e., oculardysfunctions) of any ocular disorder that is bilateral in nature. Forexample, ocular dysfunctions that occur in disorders such as theglaucoma group of eye diseases, optic neuritis, retinal pathologies,etc. can be detected using the present invention.

Turning to the drawings, FIG. 1A shows a device 10 for exposing an eye52A-B to a series of flashes and FIG. 1B shows device 10 whenimplemented as part of a system for detecting an ocular disorder. InFIG. 1A, device 10 is shown including a pair of eye scopes 12A-B. Eacheye scope 12A-B is shown including an ocular aperture 23A-B, amonitoring aperture 20A-B, and a light aperture 25A-B. Further, mirrors18A-B, and achromatic lenses 16A-B are shown disposed within eye scopes12A-B, and light sources 26A-B are shown positioned proximate to lightapertures 25A-B in eye scopes 12A-B. To test a patient's eyes 52A-B, thepatient places both eyes 52A-B so that light passing out of eye scopes12A-B through ocular apertures 23A-B will enter the eyes 52A-B.Subsequently, one of light sources 26A-B generates a series of flashes(i.e., multiple brief instances of light) that pass through thecorresponding light aperture 25A-B, are reflected by the correspondingmirror 18A-B, and pass through the corresponding ocular aperture 23A-Balong path 34A-B in the direction shown. As each flash passes throughthe ocular aperture 23A-B, the corresponding pupil 54A-B of the eye52A-B responds by adjusting to a certain size/position.

To assist in correctly placing eyes 52A-B for testing, eye scopes 12A-Bare shown mounted on an interocular distance adjuster 32. Interoculardistance adjuster 32 can be used to adjust the distance between eyescopes 12A-B to correspond with the distance between a particularpatient's eyes 52A-B. Further, FIG. 1B shows interocular distanceadjuster 32 mounted to a support mechanism 15. In addition to providingstability to eye scopes 12A-B, support mechanism can provide upward anddownward adjustments of eye scopes 12A-B. FIG. 1B also shows device 10including head holder frames 33A-B that include sensor switches 80A-B,81A-B. Head holder frames 33A-B can assist in holding a patient's headin its desired position during testing, while sensor switches 80A-B,81A-B can generate a signal (e.g., illuminate a light) when thepatient's head is in the desired position for testing. The location ofsensor switches 80A-B, 81A-B can be adjusted to conform to various headsizes.

As discussed, an eye 52A-B is exposed to a series of flashes generatedby one of light sources 26A-B during testing. It is understood thatdevice 10 could include a single light source 26A that generates theseries of lights for both eye scopes 12A-B. For example, light source26A could be moved between eye scopes 12A-B, a system of movable mirrorscould be implemented, etc. In one embodiment, each light source 26A-Bcomprises a light emitting sphere. FIG. 2 shows a preferred embodimentfor light emitting sphere 26A adjacent eye scope 12A (FIG. 1A). It isunderstood that light emitting sphere 26B adjacent eye scope 12B issimilar and, accordingly, has like elements. As shown, light emittingsphere 26A comprises an outer portion 31A, a reflective well portion33A, and an exit port 35A. Disposed along outer portion 31A are aplurality of monochromatic light sources 29 and, optionally, infraredlight sources (e.g., light emitting diodes (LEDs)). In one embodiment,monochromatic light sources 29 positioned about the outer portion 31A,comprise at least four different, non-spectrally-adjacent hues. Forexample, monochromatic light sources 29 can include light sources 29that generate hues and corresponding peak emission wavelengths thatcorrespond to blue (approximately 430 nanometers), green (approximately560 nanometers), yellow (approximately 585 nanometers), and red(approximately 660 nanometers). It is understood, however, that otherdiffering peak emission wavelengths, may be incorporated.

As further shown in FIG. 2, monochromatic light sources 29 point inwardtoward reflective body portion 33A. As a result, the light emitted fromeach monochromatic light source 29 shines into sphere 26A, reflectsthroughout reflective well portion 33A and eventually reflects backthrough exit port 35A as a single beam of light 34A in aperture mode. Asbeam of light 34A passes through exit port 35A, it may pass through apolarizing screen 28A. Polarizing screen 28A can be used to reduce anylight artifact when testing a patient under the bright conditions. It isunderstood that the light will be reflected throughout the entirereflective well portion 33A. The limited number of reflections shown inFIG. 2 is for clarity of illustration.

The use of reflected monochromatic light presented in aperture modeinstead of direct monochromatic light provides uniformly intenseillumination of a limited region of the patient's visual field.Moreover, the use of reflected light is advantageous because no singlelight source 29, when flashed, may be intense enough to generate apupillary reflex by pupil 54A-B by itself Therefore, in order to produceenough stimulus intensity to drive the pupil's reflexes, severalmonochromatic LED sources 29 can be “combined” (integrated) by lightemitting sphere 26A-B to form beam of light 34A on which the patient'seyes 52A-B should be fixated.

Referring back to FIGS. 1A and 1B, light sources 26A-B may also eachinclude a fixation point 40A-B to which the patient can direct his/hergaze as is known in the art. Fixation points 40A-B provide a centralpoint on which patients should focus while looking into eye scopes 12A-Bthrough ocular apertures 23A-B. When focused on a central point, thetesting procedures, described in more detail below, are more accuratelyperformed because the patient's eyes 52A-B do not wander. Each fixationpoint 40A-B can be provided by two single light sources, via beamsplitters, etc. Such fixation arrangements are well known in the art.

The pupillary reflexes of both eyes 52A-B are measured while one eye52A-B is being exposed to the series of flashes. To assist in measuringthe pupillary reflexes of eyes 52A-B, device 10 is also shown in FIG. 1Aas including a pair of light sources 41A-B and a pair of achromaticlenses 16A-B. Light from light sources 41A-B reflects off of eyes 52A-Band passes through ocular apertures 23A-B within eye scopes 12A-B alongview paths 38A-B in the direction shown. In one embodiment, lightsources 41A-B comprise infrared light sources and mirrors 18A-B comprisecold mirrors. The use of infrared light and cold mirrors allows thevisible light generated by light sources 26A-B to be deflected bymirrors 18A-B while the infrared light passes through mirrors 18A-B andis allowed to continue towards monitoring apertures 20A-B. Achromaticlenses 16A-B can be used to focus the resulting images of eyes 52A-B forimproved measurements of the pupillary reflexes. Still further, infraredlight filters 30A-B can also be positioned between a measuringinstrument and the patient's eyes 52A-B to ensure that only infraredlight reaches the measuring instrument. In this case, infrared lightfilters 30A-B filter out any non-infrared light that may have passedthrough cold mirrors 18A-B. It is understood that infrared filters 30A-Bcould alternatively be provided as a single filter and can be locatedanywhere between patient's eyes 52A-B and the measuring instrument.

As shown in FIG. 1B, infrared light sources 41A-B may comprise aplurality of infrared lights 27 positioned around eyes 52A-B. Forexample, infrared light sources 41-B could be provided as a ring ofinfrared lights 27 positioned about the periphery of ocular apertures23A-B of each eye scope 12A-B. In one embodiment, infrared lights 27comprise light emitting diodes (LEDs). In addition, infrared lights 27can be scuffed or the like so that the light generated by each infraredlight 27 is dispersed about a greater surface area of the patient'spupil and as near axial as possible.

During testing, as the test eye 52A-B is exposed to the series offlashes, light sources 41A-B emit infrared light to both eyes 52A-B. Theinfrared light reflects off eyes 52A-B, passes through eye scopes 12A-B,and through monitoring apertures 20A-B, thereby allowing images of eyes52A-B to be captured by recording mechanisms 36A-B. In one embodiment,recording mechanisms 36A-B comprise charged coupled devices withsignificant infrared sensitivity corresponding to the emission ofinfrared lights 27. However, other known recording means may be used.Further, recording mechanisms 36A-B can provide optical magnification ofthe images for improved analysis. In any case, recording mechanisms36A-B record the pupillary reflexes of both eyes 52A-B simultaneously,and can output the recordings to computer system 42 via I/O mechanism48. The recordings can be converted into recording data by softwareproduct 44. Software product 44 can be any number of products known inthe art. Computer system 42 can process the recording data to generatean image 56 of one or both eyes 52A-B on video display 55. Further,computer system 42 and/or recording mechanisms 36A-B can determine ifthe detected pupillary reflexes meet required criteria. For example,only recorded pupillary reflexes that have required criteria comprising:a) measured culmination times of about 0.5 seconds, b) finite latencies,and c) no eye blinks during the recording interval may be accepted. Therecording duration for the direct and consensual reflexes can beuser-defined, however a duration of approximately one and a half secondscan be used as a default recording interval. If one or both of thepupillary reflexes do not meet all of the required criteria, the eye canbe re-exposed to the flash after a suitable interval (e.g., tenseconds).

The recording data can also be processed to generate image data/graphs57 for display on video display 55. For example, the dimension of one orboth pupils 54A-B can be displayed in a graph as a function of time. Inone embodiment, software product 44 identifies the pupil component ofthe image and counts the number of pixels in the pupil component of theimage to determine the dimensions (e.g., diameter) of pupils 54A-B.Alternatively, software product 44 can implement a scanning linetechnique with infrared light, as disclosed in U.S. Pat. No. 3,533,683to Stark et al., hereby incorporated by reference. In any event, oncethe dimensions of pupils 54A-B are determined, the presence of an oculardysfunction in one or both of eyes 52A-B can be determined.

FIGS. 5A and 5B show illustrative graphs 400A-B generated from therecording data that can be displayed on video display 55 for analysis byan operator. Graph 400A represents recording data when a left eye wasexposed to the flash, and graph 400B represents recording data when aright eye was exposed to the same flash. In both cases, the flashcomprised a bright blue beam of light. In each graph 400A-B, the videoframes that were recorded in a time interval of 1.75 seconds followingthe onset of a flash were analyzed to generate the data shown. In thiscase, the pupil size is shown as a number of video scan lines obtainedfrom each video frame. In each graph 400A-B, data for both the exposedeye (direct) as well as the other eye (consensual) are charted. Graphs400A-B allow an operator to visually analyze the pupillary reflexes ofboth eyes to the exposed flash.

Returning to FIG. 1B, the system further includes a control panel 50having one or more control adjusters 51. Control adjusters 51 allow anoperator to adjust the video features (e.g., height and width) of animage as it appears on the video display 55 and to define a region ofinterest in the video image. In particular, an operator can adjust thevertical and/or horizontal dimensions of a window of interest of thevideo display 55 and the location with reference to the corneal regionof the eye to be captured by the recording mechanisms 36A-B.

Electronic overlay board 46 can also be included in computer system 42for producing an electronic overlay. The electronic overlay can be usedto further limit the fields of view of recording mechanisms 36A-B. Theoverlay feature can be enabled by overlay board 46 in computer system 42and can be implemented using technology known in the art. The electronicoverlay can also be positioned by one or more control adjusters 51.Control adjusters 51 can allow a user to customize the field of view fora particular patient as the user views images 56 of eyes 52A-B on videodisplay 55. Specifically, once a patient is properly positioned sopupils 54A-B are in the field of view, an operator can view videodisplay 55 and adjust (position and size) the overlay 60 until it onlyoverlays pupils 54A-B of the patient. Once the overlay is in its properposition, and the threshold is set, the image is ready for processing.In one embodiment, overlay area 60 is circular and can be sized to fitwithin the pupil. A narrower overlay may be used as long as it covers,i.e. can measure, the pupil diameter.

For example, FIG. 3 shows an image of eye 52A without the overlayfeatures. As shown, the field of view 64 extends beyond the pupillaryboundary (the periphery of the pupil 54A) and includes noise 62. Forexample, noise 62 may comprise a series of bright points that may begenerated when infrared lights 27 (FIG. 1B) are used to illuminate eye52A. In any event, noise 62 may interfere with the accurate analysis ofthe eye image and its corresponding dimensional data. As shown in FIG.4, the use of an electronic overlay limits the field of view ofrecording mechanism 36A (FIG. 1A) to an overlay area 60 that is definedprimarily by pupil 54A, thereby excluding noise 62 and/or any otherextraneous features.

FIG. 6 shows illustrative method steps for testing eyes 52A-B (FIG. 1A)according to one embodiment of the invention. In the embodiment shown,eyes 52A-B are exposed to a “block” of flashes in step S2. A block offlashes comprises a series of flashes to which each eye 52A-B of thepatient is exposed. In one embodiment, a first eye can be exposed to theseries of flashes, followed by the second eye being exposed to the sameseries of flashes. Each flash in the series of flashes varies from theother flashes in the series by at least one of: location in the visualfield, luminosity, and/or chromatically. In the embodiment shown, eachflash in the series of flashes to which each eye is exposed in step S2varies chromatically from the other flashes in the series. For example,the series of flashes can comprise four flashes, in which the firstflash is red, followed in order by green, blue, and yellow flashes.Further, the series of flashes is repeated for each combination of twosettings for luminosity (i.e., dim and bright), and two locations forthe field of view (i.e., periphery and central). It is understood,however, that numerous variations are possible.

In any event, once a patient is properly positioned proximate device 10(FIG. 1A) for testing, eyes 52A-B can be illuminated using light sources41A-B (FIG. 1A) in step S1, and the settings for a first block offlashes are set so that each flash has a dim intensity, and a locationin a periphery of the visual field. In step S2, the eyes are exposed tothe block of flashes. FIG. 7 shows illustrative steps used to expose theeyes to the block of flashes. In this case, each flash in the series offlashes varies chromatically from the other flashes in the same seriesof flashes. In step S21, device 10 (FIG. 1A) is set to expose a firsteye to the first flash in the series of flashes. In step S22, the eye isexposed to the flash. In step S23, it is determined if the pupillaryreflexes that were detected by, for example, recording mechanisms 36A-B(FIG. 1A) include the required criteria (e.g., eyes did not blink). Ifthe pupillary reflexes do not meet the required criteria, the flash isrescheduled in step S24 to be re-exposed at the end of the block. Instep S25, it is determined if there are any additional flashes in theseries. If additional flashes remain, device 10 is set to expose thenext flash in step S26, and flow returns to step S22 where the flash isexposed. Once all flashes in the series have been exposed, it isdetermined in step S27 if both eyes have been exposed to the series. Ifonly the first eye has been exposed, flow continues to step S28 in whichdevice 10 is set to expose the second eye to the first flash in theseries, and flow returns to step S22 where the flash is exposed. Oncethe series of flashes has been exposed to both eyes, flow continues tostep S29 wherein any rescheduled flashes are re-exposed in a similarmanner. To re-expose each rescheduled flash, the eye and thecorresponding flash in the sequence are stored and device 10 is setappropriately between each flash. It is understood that the method stepsare only illustrative, and various alternatives are possible. Forexample, a flash can be rescheduled to occur at the end of the series offlashes, or the flash could be re-exposed as the next flash.

Returning to the embodiment shown in FIG. 6, once the eyes have beenexposed to the block of flashes in step S2, it is determined whatintensity was used in step S3. If the dim setting for luminosity wasused, then the luminosity is set to the bright setting in step S4, andflow returns to step S2 wherein the eyes are exposed to the block offlashes using the new luminosity setting. If the bright luminositysetting was used, the location setting that was used for the block offlashes is determined in step S5. If the periphery location was used,then the location setting is changed to the central location in step S6.Additionally, the luminosity setting is changed back to dim so that boththe dim and bright settings will be used for the new location. Once theeyes have been exposed to the block of flashes having bright intensityand located in the central location of the field of view, the test isended in step S7.

In one embodiment, each series of flashes comprises four flashes (e.g.,red, green, blue, yellow). Consequently, each block of flashes wouldcomprise eight flashes. Further, each flash in each series of flashescan be spaced from a previous flash by approximately ten seconds. Whenrepeated for each combination of two luminosity settings, and twodifferent locations in the field of view, each block of flashes would beperformed four times. As a result, the entire test (i.e., thirty-twoflashes) can be run in approximately five minutes (without anyrescheduled flashes).

As previously noted, the recorded pupillary reflexes can be processed todetect the presence of an ocular dysfunction. For example, the pupilsizes can be used to determine the Relative Afferent Pupillary Defects(RAPD) evoked by each flash. By exposing both eyes to the same series offlashes, and simultaneously measuring the direct and consensualpupillary reflexes for each flash, two values for the RAPD can becalculated. First, when the left eye was exposed to the series offlashes, the RAPD for each flash can be calculated by subtracting thedirect pupillary reflex of the left eye (OSD) from the consensualpupillary reflex of the right eye (ODC), or ODC-OSD. Second, the RAPDcan be calculated when the right eye was exposed to the same series offlashes. In this case, the RAPD for each flash can be calculated bysubtracting the consensual pupillary reflex of the left eye (OSC) fromthe direct pupillary reflex of the right eye (ODD), or ODD-OSC. Anon-zero result for either of the calculations indicates that an oculardysfunction is present. The size of the difference provides someindication of the extent of the dysfunction. Further, the sign of thedifference indicates the eye in which the defect is present. Forexample, since the left eye was subtracted from the right eye for eachflash in the table below, a positive value indicates a left afferentdefect (LA) and a negative value indicates a right afferent defect (RA).

RAPD Magnitudes and Their Classification as Left or Right AfferentDefects as Determined from Reflex Amplitudes S - POAG Red Yellow GreenBlue Bright Disk ODC - OSD defect 0.45 (LA)  0.30 (LA) 0.30 (LA) 1.15(LA) ODD - OSC defect 1.45 (LA) −0.25 (RA) −1.25 (RA)  1.35 (LA) BrightRing ODC - OSD defect 0.95 (LA) −2.00 (RA) 2.80 (LA) 4.65 (LA) ODD - OSCdefect 2.65 (LA) −3.30 (RA) 1.25 (LA) 1.30 (LA) Dim Disk ODC - OSDdefect −0.95 (RA)   0.55 (LA) 0.40 (LA) −2.10 (RA)  ODD - OSC defect0.00  0.25 (LA) 2.30 (LA) −1.20 (RA)  Dim Ring ODC - OSD defect 2.85(LA)  0.20 (LA) 1.90 (LA) 0.65 (LA) ODD - OSC defect 5.65 (LA) −0.15(RA) 2.10 (LA) 5.30 (LA)

A multivariate mode of analyses can also be used to further discriminatebetween the various optic dysfunctions of, for example, patientsdiagnosed with the glaucoma group of diseases. For example, the Pearsonproduct moment correlation coefficients between the matrices of theRAPDs of any number of selected patients' eyes can be calculated so asto determine the extent of the resemblance between the pattern of RAPDsof each of these patients' individual eye or eyes. In order to obtainthe best results, the flashes can be provided in the same, or as closeto the same as possible, sequence to each patient. A high correlationbetween the ocular dysfunctions of a first patient and a second patientknown to have a particular ocular disorder may indicate that the firstpatient also has the ocular disorder. When data from numerous patientsis used for each disorder, a set of inter-correlation matrices can beconstructed as shown in FIG. 8. The inter-correlation matrices canprovide the ability to compare relevant correlations between a testpatient's data and that of index patients having various diagnosedocular disorders. The inter-correlation matrices allow precisequantitative assessment of the resemblance of the data recorded for atest patient to the data recorded for patients clinically diagnosed ashaving various ocular dysfunctions.

It is understood that the invention can be realized in hardware,software, or a combination of hardware and software. Any kind ofcomputer/server system(s)—or other apparatus adapted for carrying outthe methods described herein—is suited. A typical combination ofhardware and software could be a general-purpose computer system with acomputer program that, when loaded and executed, carries out therespective methods described herein. Alternatively, a specific usecomputer, containing specialized hardware for carrying out one or moreof the functional tasks of the invention, could be utilized. Theinvention can also be embedded in a computer program product, whichcomprises all the respective features enabling the implementation of themethods described herein, and which—when loaded in a computer system—isable to carry out these methods. Computer program, software program,program, or software, in the present context mean any expression, in anylanguage, code or notation, of a set of instructions intended to cause asystem having an information processing capability to perform aparticular function either directly or after either or both of thefollowing: (a) conversion to another language, code or notation; and/or(b) reproduction in a different material form.

The foregoing description of various aspects of the invention has beenpresented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed, and obviously, many modifications and variations arepossible. Such modifications and variations that may be apparent to aperson skilled in the art are intended to be included within the scopeof the invention as defined by the accompanying claims.

1. A method comprising: exposing a first eye of a patient to at leastone series of flashes, wherein each of the at least one series offlashes includes flashes that vary chromatically from the other flashesin the same series of flashes; and concurrently recording image data ofthe first eye and a second eye of the patient during the exposing. 2.The method of claim 1, further comprising repeating the exposing andrecording for the second eye.
 3. The method of claim 1, furthercomprising illuminating the first and second eyes prior to the exposing.4. The method of claim 1, further comprising measuring pupillaryreflexes of the first eye and the second eye as a result of the exposingbased on the image data for the first eye and the second eye.
 5. Themethod of claim 1, wherein at least one flash in each of the at leastone series of flashes is a red flash.
 6. The method of claim 5, whereinthe red flash has no photochromatic interval.
 7. The method of claim 1,wherein at least one flash in each of the at least one series of flashesprovides a uniformly intense illumination of a portion of a visual fieldof the first eye.
 8. The method of claim 1, further comprisinggenerating a set of graphs for presentation on a video display based onthe image data.
 9. The method of claim 1, wherein at least one flash ineach of the at least one series of flashes is a white flash.
 10. Themethod of claim 1, wherein each flash in each of the at least one seriesof flashes comprises a duration less than a start of a release phase ofa pupillary reflex of the first eye in response to the flash.
 11. Themethod of claim 10, wherein each flash in each of the at least oneseries of flashes is separated from an adjacent flash in the same seriesof flashes by approximately ten seconds.
 12. The method of claim 1,wherein each of the at least one series of flashes includes at leastfour flashes.
 13. A system comprising: at least one light sourceconfigured to generate light of varying chromaticity; a componentconfigured to direct the generated light towards one of a pair of ocularapertures; at least one recording mechanism configured to concurrentlyrecord image data of a first eye and a second eye located adjacent tothe pair of ocular apertures; and a component configured to generate afirst series of flashes using the at least one light source, wherein thefirst series of flashes includes flashes that vary chromatically fromthe other flashes in the same series of flashes.
 14. The system of claim13, further comprising an interocular distance adjuster configured toadjust a distance between the pair of ocular apertures.
 15. The systemof claim 13, further comprising at least one infrared light sourceconfigured to illuminate the first eye and the second eye with infraredlight.
 16. The system of claim 13, further comprising a componentconfigured to measure a direct pupillary reflex of one of the first eyeor the second eye and a consensual pupillary reflex of the other of thefirst eye or the second eye as a result of the one of the first eye orthe second eye being exposed to a flash based on image data of the firsteye and the second eye recorded during and immediately after the flash.17. The system of claim 16, further comprising a component configured togenerate a graph for presentation on a video display based on themeasured pupillary reflexes.
 18. The system of claim 16, furthercomprising a component configured to determine whether the directpupillary reflex and the consensual pupillary reflex were detected inthe image data.
 19. A system comprising: a component configured togenerate at least one series of flashes for exposure to a first eye of apatient, wherein each of the at least one series of flashes includesflashes that vary chromatically from the other flashes in the sameseries of flashes; and at least one recording mechanism configured toconcurrently record image data of the first eye and a second eye of thepatient during the at least one series of flashes.
 20. The system ofclaim 19, wherein the component configured to generate includes: atleast one light source configured to generate light of varyingchromaticity; and a component configured to direct the generated lighttowards one of a pair of ocular apertures.
 21. The system of claim 20,further comprising an interocular distance adjuster configured to adjusta distance between the pair of ocular apertures.
 22. The system of claim19, further comprising at least one infrared light source configured toilluminate the first eye and the second eye with infrared light duringthe at least one series of flashes.
 23. The system of claim 19, furthercomprising a component configured to measure pupillary reflexes of thefirst eye and the second eye as a result of the at least one series offlashes based on the image data for the first eye and the second eye.24. The system of claim 19, further comprising a component configured todetermine whether pupillary reflexes of the first eye and the second eyein response to a flash in the at least one series of flashes weredetected in the image data.